Abstract:
This review summarized the methods of estimating soil characteristics using ground penetrating radar (GPR), such as analyses of reflections, ground wave, surface reflection coefficient, full-waveform inversion and early-time signal analysis. This study analyzed the basic principle and method using GPR to detect soil characteristics in detail, and reviewed the ability and limitation of GPR by summarizing latest studies. The approaches based on signal velocity analysis were widely used; however, the results were subjective and limited by the experimental environment. The approaches based on reflection amplitude analysis were limited by varying soil water contents with depths and surface roughness, and which leaded to a decrease in reflection coefficient. The full waveform inversion and early-time signal analysis methods emphasized the importance of data acquisition and processing in detection. More complex numerical analysis models and data processing approaches should be developed to improve data acquisition speed and measurement accuracy.